Prevention and remediation of petroleum reservoir souring and corrosion by treatment with virulent bacteriophage

Abstract

There is provided a safe, natural, environmentally sound means of controlling bacterial contamination, corrosion, and souring of oil and gas wells and reservoirs that result from bacteria-contaminated water in a well. In one aspect it is a process for remediation of souring of petroleum reservoirs and coalbeds by adding to the water used in flooding and “fracing” operations an effective amount of virulent (non-lysogenic) bacteriophages (phages) specific for problematic target bacteria. The invention also provides a means for combating loss of effectiveness of bacterial control by staging bacteriophage production and application to control dominant and sub-dominant target bacteria in a community of target bacteria.

The invention claimed is: 
     
       1. A process for remediation of souring of oil, gas and coalbed geological reservoirs comprising adding to the water used in a hydrofracturing or flooding operation an effective amount of virulent bacteriophage derived from non-lysogenic bacteria and specific for target bacteria, the target bacteria comprising acid producing bacteria and sulfate reducing bacteria. 
     
     
       2. The process of  claim 1  wherein the virulent bacteriophage comprises a multi-panel of virulent bacteriophages, each having at least two bacteriophages virulent for each species of target bacteria. 
     
     
       3. The process of  claim 1  wherein the effective amount of bacteriophage comprise bacteriophage indigenous to the general location where it is to be applied to remediate reservoir souring. 
     
     
       4. The process of  claim 1  wherein a solution of bacteriophage has a concentration of bacteriophage of about 1×10 7  to 1×10 10  pfu/ml. 
     
     
       5. The process of  claim 1  wherein target bacteria comprise sulfate reducing bacteria, sulfuroxidizing bacteria capable of generating sulfuric acid, and iron-oxidizing bacteria. 
     
     
       6. The process of  claim 1  comprising:
 providing a water pond or storage tank, 
 adding a solution of bacteriophages virulent for target bacteria to the pond or storage tank solution to at least 1×10 5  pfu/ml, and 
 injecting an effective amount of the resulting solution into the reservoir. 
 
     
     
       7. The process of  claim 6  wherein the target bacteria comprise sulfur reducing bacteria.